The present invention relates to a data recording equipment, a controller of a data recording equipment, and a method for recording data.
An optical disc is known as a recording medium that records data. A CD-R, which is one type of optical disc, records data only once, for example, in disc units or track units. The CD-R is widely used due to its superior cost efficiency per unit of data.
A spiral pregroove, which is a guide groove, is formed in the CD-R. The pregroove wobbles in a cyclic manner. Information, such as the position on the disc (i.e., absolute time) and the respective maker's, specifications is written in correspondence with the wobbles. When data is recorded in the guide groove, an absolute time in pregroove (ATIP) address that shows the absolute time information on the optical disc is read from the pregroove. Data is then recorded while using the ATIP address to accurately ascertain the data recording position on the disc.
A recording equipment that records data on a CD-R normally includes:
an encoder for adding data position information to data input by an external device and for performing eight to fourteen (EFM) modulation;
a recording laser drive circuit for emitting a laser beam on an optical disc in accordance with the data encoded by the encoder;
a read laser drive circuit for emitting a laser beam, which is used to reproduce data, on an optical disc and reading an ATIP addresses to find the absolute time in the optical disc; and
a decoder for reading an ATIP address by decoding a reflection of a laser beam.
Data is recorded on the optical disc while reading ATIP addresses from the optical disc with the read laser drive circuit and the decoder. This records the data at predetermined positions on the optical disc.
There is a possibility of a shock being applied to the data recording equipment when data is being recorded on the optical disc. This may momentarily change the disc position irradiated by the laser beam. As a result, recording positions may be skipped. When skipping occurs, a gap may be produced in the data recorded on the optical disc. In addition, the recording of data while reading ATIP addresses becomes difficult.
This problem occurs not only when a shock is applied to the data recording equipment but also when the recording of data is automatically interrupted to avoid a buffer underrun error. Further, equipments that record data on other types of optical discs, such as a compact disc-rewritable (CD-RW), and equipments that record data on a magneto-optic disc (MO) or a mini disc (MD) may have the same problem. In this specification, optical discs include magneto-optic discs unless otherwise specified.